The United States’ rate of entrepreneurial activity dropped in 2012 for the second year in a row, according to a new study by the Kauffman Foundation. The report found that 0.30 percent of adult Americans were involved in starting a business last year, down from 0.32 percent in 2011. That means 514,000 people were starting businesses each month in 2012, compared with 543,000 in 2011. Don’t blame women for this decline — their entrepreneurial activity rate remained steady at 0.23 percent. Instead,…